This application is the national phase under 35 U.S.C. xc2xa7371 of PCT International Application No. PCT/DE00/02709 which has an International filing date of Aug. 11, 2000, which designated the United States of America, the entire contents of which are hereby incorporated by reference.
The present invention generally relates to a combination of a contactor and a soft starter.
In electrical drive technology, electronic soft starters are often used in addition to contactor control in order to protect motors and mechanical drive elements, such as transmissions or pulley belts. A further advantage of using these soft starters is that it reduces the current surges when starting three-phase motors.
The known soft starters are autonomous appliances, which are mounted separately in switchgear cabinets. The connection to the other switching devices (contactor, circuit breaker, overload relay) for a motor outgoer is provided by electrical cables.
One important cost criterion for the user is the space requirement for the switching devices for a motor outgoer in the switchgear cabinet. In this case, width is an important criterion.
An object of an embodiment of the present invention is to arrange the switching devices for a motor outgoer in a minimal area in a switchgear cabinet.
Such an object is achieved by a soft starter mounted on the contactor.
Such a configuration results in the soft starter and contactor forming a physical unit, which requires only the same width as the contactor.
The soft starter can be mounted on the contactor, for example, by the contactor having a mounting face and an operating face which is opposite the mounting face. In this case the contactor can be mounted by the mounting face on a holding element, and the soft starter can be arranged on the operating face of the contactor.
The contactor can be connected to the soft starter particularly easily if the contactor and the soft starter include interacting hook elements, by which the soft starter can be held on the contactor.
If the contactor and the soft starter include interacting latching elements which, when operated, allow the soft starter to be detached from the contactor, the soft starter can easily be detached from the contactor once again.
If the contactor and the soft starter include interacting supply contact elements, by which the soft starter can be supplied with electrical power via the contactor, no dedicated cables need be laid to supply power to the soft starter.
If the contactor and the soft starter include interacting load contact elements, by which at least one load current cable is connected from the contactor to the soft starter, there is no need either to lay dedicated load cables between the contactor and the soft starter.
If the contactor connects a three-phase power supply system to a three-phase load and the soft starter is a single-phase soft starter, by which only one phase of the three-phase power supply system can be influenced, the wiring complexity when using separately laid load cables can be minimized if the phase which can be influenced is connected via the soft starter to the three-phase load and the two other phases are connected directly via the contactor to the three-phase load.
If the contactor includes a physical contactor width, the soft starter includes a physical soft starter width. Further, if the physical contactor width is at least as great as the physical soft starter width, the soft starter does not project beyond the contactor at the sides.
If the contactor includes a physical contactor height, the soft starter includes a physical soft starter height. Further, if the physical contactor height is greater than the physical soft starter height, the cables can easily be connected to the contactor, even if the soft starter is already fitted.